I would most definitely condone it. As humans, gene therapy is not essential for our survival, though I'll admit that it may be helpful in treating certain diseases. However, if human genetic engineering were allowed, it's a sure way to create an even larger gap between the rich and the poor. Genetic engineering is expensive, and while it may be best for the child, the rich would most definitely use it to their advantage, while those who cannot afford it will give birth to their children naturally, and hence a "superior race" will be born. Genetic engineering for human enhancement will most definitely lead to genetic discrimination and prejudice, and honestly speaking, we don't need more ways to discriminate. Adolf Hitler attempted to create a "superior race" of Germans, but luckily, he lacked the technological means to do so effectively.
You would personally accept this notion of genetic engineering? I think you should see a film called Gattaca. One of the best science-fiction films ever, it elucidates the debate over tampering with human genetics. Watch the film, then come back to this debate. You'll understand the controversy behind human genetic engineering a lot better than reading those books that you mightn't understand.
It's fascinating though, what you can do with technology.